1. Field Of The Invention
The present invention relates to an ink cartridge accommodating ink and an ink cartridge connection mechanism for an ink jet recording apparatus which forms an image on a recording medium by jetting ink drops in accordance with image information.
2. Description of the Related Art
Conventionally, an ink jet recording apparatus has been used which supplies ink to a cavity of an ink jet recording head having, for example, a piezoelectric element as pressure means and pressurizes the ink accommodated in the cavity by driving the aforesaid piezoelectric element to jet the ink from a nozzle connected with the cavity and to form an image on a recording medium.
Supplying ink to the aforesaid ink jet recording apparatus is performed, as shown in FIG. 11, by connecting an ink cartridge 205 accommodating ink with an ink cartridge accommodating portion 203 which is provided in a carriage 201 retaining an ink jet recording head 200.
The aforesaid ink cartridge 205 has a box-shaped main body. The upper part of the inside thereof is divided into an ink accommodating section 209 and a filler accommodating section 211 by a partition plate 207. In the filler accommodating section 211, a filler 213 made of porous material is accommodated. This filler 213 is fixed by ribs 215 and 217 which are provided on an internal ceiling part and a floor part, respectively. A venthole 219 is formed in the ceiling part of the filler accommodating section 211, and an ink supplying port 221 is formed in the floor part. At the outlet of the ink supplying port 221, formed is a cylindrical shaped pressure pin inserting portion 223.
Ink is accommodated in the ink accommodating section 209 and permeates into the filler 213 at a connection part 225 which is positioned at the lower edge portion of the partition plate 207 and connects the ink accommodating section 209 and the filler accommodating section 211.
In the ink cartridge accommodating portion 203, a concave portion 227 accommodates the aforesaid pressure pin inserting portion 223. On the bottom part of this concave portion 227, a pressure pin 229 is protrusively provided. The pressure pin 229 is inserted into the pressure pin inserting portion 223 when the pressure pin inserting portion 223 is accommodated in the concave portion 227. On the edge of the concave portion 227, an O-shaped ring 231 is attached to gaplessly connect the concave portion 227 with the pressure pin inserting portion 223. The tip of the pressure pin 229 is pointed so as to stick into the filler 213, and an ink inlet 235 is formed which is connected with an ink path 233 formed inside the pressure pin 229. The aforesaid ink path 233 is connected with an ink supplying path 237 of the ink jet recording head 200.
When the ink cartridge 205 arranged as described above is connected with the ink cartridge accommodating portion 203, the pressure pin 229 is inserted into the pressure pin inserting portion 223 and the tip thereof sticks into the filler 213, thereby the ink permeated in the filler 213 enters through the ink inlet 235 and is supplied to the ink jet recording head 200 through the ink path 233 and the ink supplying path 237.
However, according to the ink cartridge 205 having the aforesaid arrangement, since ink permeates into the filler 213 not only in the case that ink is left inside the ink accommodating section 209 but also in the case that the ink otherwise accommodated in the ink accommodating section 209 is exhausted, such a problem occurs wherein ink leaks from the ink supplying port 221 in exchanging the ink cartridge 205. If an openable lid (not shown) is provided over the ink supplying port 221 to prevent the leakage of ink, the problem is caused that the open and close mechanism of the lid causes increase of producing cost of ink cartridges.
Further, when the pressure pin 229 penetrates to the filler 213, both ink and including air may enter the ink inlet 235. If the ink including air in this way is supplied to the ink jet recording head 200, this air becomes bubbles to act as a damper inside an ink pressure section (cavity) for pressurizing ink and the pressurization of ink is disturbed, thereby desired ink drops cannot be formed and discharged from ink jet recording head 200. Accordingly, the problem is present that known ink jet recording apparatuses are not able to form excellent images in some cases.